Micro Electro-Mechanical System (MEMS) inertial sensors, including accelerometers, gyroscopes and magnetometers, are generally well-known and commercially available from Honeywell International, Incorporated, the assignee of the present patent application. These MEMS inertial sensors are typically mounted as individual units directly on the host structure to be monitored. While effective, such direct mounting places increased demands on the precision and accuracy with which the structure to be monitored is manufactured in order to achieve true three-axis orientation. Nor can direct mounting on the host structure obtain the small size advantages offered by the MEMS sensors. Furthermore, assembly and testing of the MEMS sensors requires access to and manipulation of the entire host structure. These limitations in turn limit the performance that can be achieved by the MEMS sensors.